Method of minimizing erosion in ordnance and preventing flareback.



UNITED STATES PATENT QFFTCE,

HUDSON MAXIM, OF HOPATCONG, NEW JERSEY.

METHOD OF MINIMIZING EROSION IN ORDNANCE ANDPREVENTING FLAREBACK.

No Drawing.

To all whom it may concern:

Be it known that I, HtosoN Mxxnnot the borough of Hopatcong, county of Sussex, State of New Jersey, have invented a new and useful Improvement in Methods of )linimizing Erosion in Ordnance and Preventing Flareback,. which invention fully set forth in the following specification.

The present invention relates to improvements in materials and means for minimizing erosion in ordnance, and for preventing tlareback by the employment of a material or materials whose vapors or products of decomposition shall alter the chemical composition of the products of ombustion of the gunpowder charge and. also lower their temperature, thereby minimizing erosion and preventing flareback, all without injuriously attecting the ballistic results.

.l'lerctoiore many attempts have been made to so modify gunpowder charges as to lower the temperature of the products of combustion, and thereby minimize erosion, but all such attempts have been made by modifying the composition of the smokeless gunpowder itself. I

in carrying out my invention, I employ an auxiliary or cooling charge of an entirely different composition than that of the main or smokeless powder charge, which auxiliary or cooling material or charge is non-explosive and preferably contains little or no combustive material, but consists mainly of a material or materials capable of being decomposed partly or entirely-into gaseous products, thereby absorbing heat from the products of combustion of the smokeless powder charge to effect the volatilization or decomposition of the auxiliary or cooling charge, while the products of the decomposition serve to oxidize a large portion of the carbonic oxid in the products of combustion of the sn'lokeless powder charge converting the carbonic oxid into carbonic acid, while carbonates are formed also at the expense ot the carbon in the carbonic oxid ot the powder gases, thereby preventing tlareback, there being preferably a sutticient quantity of the cooling material employed to more than compensate for the heat evolved by the oxidation of the carbonic oxid to carbonic acid.

The quantity of cooling charge depends upon the character of the smokeless powder employed and upon the results aimed at--- whether to lessen erosion or prevent flare- Specification of Letters Patent.

Application filed January 24, 1908.

Patented Oct. 3, 1911.

Serial No. 412,480.

back or both. A larger quantity is needed to prevent flareback with pure Intro-cellulose smokeless powder than with a smokeless powder containing a considerable percentage of nitroglycerin, because the products of combustion of pure intro-cellulose powder are much richer in carbonic oxid, which causes flareback, while, on the other hand, the temperature of the products of combustion of the nitroglycerin composition, being higher than that of the products of combustion of pure i'iitro-cellulose powder, a smaller quantity of the cooling charge is required to prevent flareback and a larger quantity to prevent erosion.

A cooling charge of anywhere from five per cent. or less, to fifty per cent. or more of the total weight of the smokeless powder charge may be employed, by varying the composition and the structure and rate of combustion of the smokeless powder charge to meet the new requirements. For example, the smokeless powder grain may be made according to my United States Patent No. 766,455, so that a greater density of loading may be employed without the production of abnormal pressures; while the pressure can be well maintained behind the projeetile in its flight through the entire length of the gun, notwithstanding the lower temperature of the powder gases due to the use of my auxiliary cooling charge used in con junction therewith. The grains of the cooling charge may be multi-pcrforated or made in other suitable form, so that they will be decomposed or volatlllzed at an accelerating rate.

There are many materials which may be successfully employed as an auxiliary cooling charge, it being necessary simply to employ a material that will be decomposed or volatilized by the heat of the products of combustion of the smokeless powder charge, thereby absorbing heat from the products of combustion of the powder charge; and a material or materials which shall liberate oxygen or carbonic acid either to dilute the products of combustion with carbonic acid or to reduce the carbonic oxid of the prodnets of combustion to carbonic acid, thereby preventing fiareback. I

I have found very good-results from the use of oxalic acid, which is decomposed mainly into carbonic acid and aqueous vapor in the presence of the hot smokeless powder gases. ()Yalic acid has the advantage that its products of decomposition are wholly gaseous. I may also employ nitrate of potassium or nitrate of sodium or both, which are converted into carbonates at the expense of carbonic oxid in the products ,bf combustion of the smokeless powder charge, releasing oxygen, which further oxidizes the carbonic oxid of the powder gases to, carbonic acid. I may also employ bi-carbonate of sodium, which liberates carbonic acid, the residuum being converted into carbonate of sodium, but I preferably employ a mixture of bi-carbonate of sodium and nitrate of potassium, or a mixture of nitrate of potassium or nitrate of sodium and oxalic acid.

Nitrate of potassium .or nitrate of sodium employed alone or combined with bi-carbonate of potassium or bi-carbonate of sodium, possesses the advantage of having no effect upon smokeless gunpowder when mixed and stored with it, having no tendency to decompose it even in the presence of moisture, as is the case with oxalic acid. Still, it is not necessary to store the cooling material with the smokeless gunpowder.

In preparing the materials for use I finely pulverize the ingredients, the proportions of which may Vary widely. The pulverized material is then compressed into dense and hard pellets or grains or molded into any shape like smokeless powder. The grains should be sufficiently dense to retard the action of decomposition in the gun, so that the size and density of the grain may be adapted to complete decomposition within the time required for the complete combus,

tion of the smokeless powder grain with which it is employed, or so that it may be decomposed sooner than the smokeless powder charge is burned, or not completely decomposed until after the projectile has left the gun, when the decomposition will be completed by the outrushing gases, all according as may be desired. Furthermore, any suitable agglutinating material, such as a small percentage of sulphur or of parafiin or of gum or resin or sugar or other adhesive material may be employed to agglutinate the particles composing the grains or pellets of the auxiliary or cooling charge, care being taken not to employ too large a percentage of any agglut-inating agent cont-aining carbon or other combustible. The proportion of agglutinating agent may vary but I have found that from 10 to 15 per cent. of any of the agglutinating agents above mentioned produces satisfactory results. In respectto the proportion of cooling, material to oe used with the explosive the quantity may vary between wide limits varying with the nature of the explosive and the extent of cooling effect desired that the cooling grains may constitutetwenty-five per cent. of the smokeless powder charge while securing good ballistic results.

Except when. using oxalic acid or other material injurious to Intro-cellulose, the

n'mterials may be agglutinated by a colloid of intro-cellulose or by a colloid composed of intro-cellulose and nitroglycerin, not

more than from five to ten per cent. of such colloid being required. Any auxiliary cooling charge may be placed in the powder chamber of the gun in a separate envelop from the smokeless powder charge, or the grains or pellets of the auxiliary charge may be mingled with the grains or pellets of the smokeless powder charge.

lVhatis claimed is 1-. The method of minimizing erosive -action of the products of combustion of explosive charges in guns and of preventing flare-backs therein, consisting 1n burning the explosive charge in the gun in presence of non-explosive material in form of indurated uniform grams winch decomposes with absorption of heat combustion of the explosive proceeds and which liberates a noncombustible gasfor preventing flare-back.

2. The method of minimizing erosive 2 action of the products of combustion of explosive charges 1n guns and of preventing fiare-back in the same, consisting in burning the explosive charge in the gun in presence of non-explosive material in form of indurated uniform grains containing oxalic acid, said grains decomposing with absorption of heat as combustion of the explosive proceeds and with liberation of non-combustible gas for preventing fiare back. v

3. The method of minimizing erosive .action of the products of combustion of explosive charges in guns and of preventing flare-back in the same, consisting in burning the explosive charge in the gun in presence of non-explosive material in. form of indurated uniform grains containing oxalic acid and an alkali-metal nitrate decomposing with absorption of heat as combustion of the explosive proceeds and with liberation of incombustible gas for preventing flareback.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

HUDSON MAXIM.

lVitnesses LILIAN. Mum, JOHN I. WILLIAMS. 

